The man who led the Lions in South Africa in 2009 hasn't played since Ireland's final RBS 6 Nations game against Scotland on 20 March because of a nagging groin problem.
The injury forced him to miss Munster's Heineken Cup quarter-final victory over Northampton Saints and also sit out the Magners League home defeat against the Ospreys this weekend.
Munster coach Tony McGahan left out another 2009 Lion, Keith Earls, from the starting line-up for the 15-11 defeat at Thomond Park by the Ospreys, but is more hopeful that he will be able to face Biarritz.
"We're very hopeful with Ian Dowling, Doug Howlett and Keith Earls. Paul O'Connell is in a race against time at the moment, so we're just giving him every opportunity at this point," said McGahan.
The tough talking Aussie coach has admitted that Sunday's Heineken Cup semi-final in Spain "is what this year is all about" And he says he has no worries about his team bouncing back from their defeat against the Ospreys.
"We have shown already this year that if we have a disappointing result we can certainly come back from it. We will re-group this week," said McGahan.
"Next weekend is what this year is all about for us and we're chasing a Heineken Cup. We were well beaten in the end by the Ospreys, they competed on every ruck, they put a lot of pressure on us and they won turnover ball.
"It was a big game for us and we needed a result. I know we showed a little fight to come back in the game, but it wasn't enough at that stage."